Saliva vs Serum

Saliva vs Serum

Saliva testing has been used to measure hormones since the late 1960s and has many advantages over serum testing. The most significant feature of saliva testing is that it reflects the non-protein bound ‘free’ fraction of hormones at a given point of time.1
As steroid hormones are predominantly bound to carrier proteins (cortisol binding protein, sex hormone binding globulin and albumin) in the blood, the unbound fraction is considered more readily available to the cells of the body (see Diagram 1). It is these ‘free’ hormones that best reflect a patient’s hormonally-related symptoms, rather than total or bound hormone levels (as measured in serum).2
Furthermore, saliva testing effectively monitors the level of supplemented hormones as well as their absorption and utilisation. Studies indicate ‘salivary progesterone measurements confirm applied progesterone is being absorbed, despite the lack of change in serum progesterone’.3 Therefore, saliva testing can influence supplementation dosages and determine if bio-identical hormone therapy is being absorbed.

Diagram 1: Steroid Hormone Carriers in Blood

diagram1

Advantages of Saliva Testing:

• Saliva reflects the free, bio-available hormone levels (unlike blood which measures total levels)
• Baseline hormone levels can be assessed and bio-identical hormone replacement therapy can be easily monitored and adjusted
• Testing is suitable for both men and women
• Simple, painless, non-invasive, economical and can be done at home
• Specimens are sent direct to the laboratory without special handling
• Multiple saliva collections can be taken over a day or a number of weeks
• Hormones are stable in saliva at room temperature
• Transport to laboratory by overnight courier from anywhere in Australasia